Shop the fashion-forward Levi's line Hailey Baldwin, SZA and more love

To celebrate 501 day, the birthday of Levi’s iconic blue jeans, the historic brand has brought together more than 20 stylish celebrities — from Amber Valletta to SZA — for its biggest celebration yet. In a portrait series to toast the launch, these celebs show us how to style the new collection.

Hollywood stylist Karla Welch, whose clientele includes such people as Karlie Kloss and Justin Bieber, was positioned to lead the creative for the exclusive nine-piece Levi’s x karla 501 Day Collection. Welch tells Yahoo Lifestyle, “It’s epic! To work with the most iconic denim in the world is a dream come true.”

For the collection, Welch put her spin on Levi’s classic 501 jeans, adding a pleat detail on one version and making the back pocket out of red patent leather on another, as well as adding it to the brand’s iconic western shirt. Other hits from the line include a fringed trucker jacket, which Welch says derives from her love for the Dallas Cowboys cheerleading outfits, not necessarily the sport. “I don’t even like football — but I remember watching Dallas with my mom and the cowgirls were in the opening montage — I loved their costumes! So the bright white and blue just brought me back!” Welch shares with Yahoo Lifestyle.

One of the standout items is the reversiblesherpa trucker jacket, worn by both SZA and Sarah Paulson in the portrait series. Don’t be surprised if you see all the “it” girls — from Bella Hadid to Kaia Gerber — sporting this jacket soon.

To toast the collection (which officially launches on Sunday, May 20), Levi’s held a special concert on Wednesday at L.A.’s famous Hollywood Palladium, featuring an all-female star lineup: SZA, Karen O (Yeah Yeah Yeahs), and Lauryn Hill.

It might seem like the female focus, from Welch to the portrait series stars, and concert bash headliners were intentional, but in fact, it all happened organically.

“It wasn’t the intent when we started out. And it is worth noting that the collection is largely unisex. But as Karla started bringing her inspiring female friends into the mix — all outspoken, authentic women with something to say — we started to see an all-female focused project as really bold and relevant in today’s cultural climate. There is such a broad range of women featured, across age, race, body type, personal style. It really emphasizes the democratic nature of the 501,” Jennifer Sey, CMO of Levi Strauss & Co., shares with Yahoo Lifestyle.

She adds, “In a time when women are being heard, speaking up, sharing their experiences, it just felt right. And hey, we’ve had all-male lineups in the past, and it was never newsworthy. Just felt like high time for the ladies to have a moment!”

In honor of the collection, Levi’s is making a donation to the Everytown for Gun Safety Support Fund. “We are so inspired by the strength and outspokenness of the young people across the country who are leading a national conversation about gun safety. It’s an important conversation centered around the health and welfare of our kids and our communities. And the equal right to safety. We aren’t prescribing an answer, just supporting the conversation,” says Sey.

Welch adds, “That’s the ethos of my company and what I do. I think it’s a new form of retail for there to be a conscious component. I want to use my platform to help get resources to organizations that advocate for social justice. Most Americans agree that we need some form of gun reform; most gun owners agree! Everytown is an organization that can help get this done.”

Ahead, see highlights from the portrait series for styling tricks, and shop the nine-piece Levi’s x karla 501 Day Collection on May 20. It retails between $150 and $420 and will be available onLevi.com, in select Levi’s® stores, and at Dover Street Market New York.